The prototype is heavily camouflaged, but we can see a long bonnet, short deck, prominent grille, a shark fin antenna and a dual exhaust system at the rear.

Cadillac has reportedly trademarked the name “LTS” which is very likely the production name for this range-topping, rear-wheel drive luxury saloon or Cadillac could continue using STS, or just name it after the concept…

The new flagship Cadillac saloon reportedly rides on the new Omega platform which also underpinned the Elmiraj concept. Rear-wheel drive will be standard but all-wheel drive could be optional. Rumour is a coupe is also planned, but nothing is official.

The base model is expected to come with a turbocharged 3.6-litre V6 producing around 420bhp and 430 lb-ft of torque. A range topping model could use an-all new V8 displacing 4.5-litres and 500+bhp.

Cadillac’s new flagship saloon is expected to debut sometimes in 2015, going against the likes of Audi A8, BMW 7 Series and Mercedes S-Class.